A. Field
This invention relates to the field of telephony and more particularly to methods for determining, in real time, the identity of the carrier that a calling or called party subscribes to, and also whether the call is from or to a mobile phone. For example, the methods are useful for determining whether a call is a mobile-to-mobile call and whether it is an intra-carrier call, that is, a call in which both the calling party and the called party subscribe to the same wireless service provider.
B. Related Art
Identification of intra-carrier mobile-to-mobile calls in real time has become more difficult in recent years in view of the advent of networks which merge CDMA wireless technology with legacy GSM wireless technology and the different technologies and protocols which are used in such hybrid systems. The identification of intra-carrier mobile-to-mobile calls is further complicated due to the impact of federally mandated so-called “local number portability,” in which a wireless subscriber is able to keep their same phone number when they switch their wireless service from one carrier to another.
Prior art of interest includes U.S. Patent Application Pub. No. 2003/0179857, which describes a telephone communications network which applies special call treatment during call setup based on whether the calling and called parties both subscriber to the same carrier. See also U.S. Pat. No. 5,333,184, which relates to service plans in which discounts may be applied to calls made by parties which subscribe to the same telephone service provider as the called party. Other prior art of interest includes U.S. Pat. No. 6,865,391, which discloses that a wireless carrier may distinguish how it sets up a particular call for a subscriber depending on whether the other party to the call is also a wireless device. U.S. Pat. No. 6,373,930 relates to processing of pre-paid calls for wireless devices.
This invention provides robust, real-time methods by which a call processing entity in a wireless telephone network infrastructure determines the identity of the carrier to which a called or calling party subscribes (or, equivalently, carrier identification for a phone used by the called or calling party). The call processing entity can thereby determine whether a call is a mobile-to-mobile call between mobile phones that subscribe to the same carrier. Identification of intra-carrier mobile-to-mobile calls allows the carrier to provide special services for the callers. Some examples of the services are different call rating (i.e., fee structure for the call), making the call a free call, and performing different routing for the call. Also, in other situations, the identity of the other carrier, and perhaps a determination of whether the call is originating from a land line or a mobile phone, may allow other procedures to be invoked, such as for example providing a discounted call rating under certain circumstances, such as where a land line phone subscribing to Carrier X is used to call a mobile phone subscribing to Carrier Y.